Numerical simulation of the 1992 Flores tsunami: Interpretation of tsunami phenomena in northeastern Flores Island and damage at Babi Island

Complex earthquake rupture and local tsunamis

“…For dislocation models, decreasing the rupture width (and thus increasing slip for a given M 0 ) has the effect of increasing the amplitude and decreasing the wavelength of the initial tsunami [ Geist , 1998] and therefore compensates for an oversimplification of the rupture process. This discrepancy is illustrated by the following examples: (1) for the 1992 Nicaragua earthquake a 70‐km‐wide rupture zone ( M 0 = 4.2 × 10 20 N m) is used in the seismic inversion of Ihmlé [1996], whereas a 40‐km‐wide rupture ( M 0 = 3 × 10 20 N m) is used in the tsunami model of Satake [1994]; (2) for the 1993 Hokkaido earthquake a 70‐km‐wide rupture ( M 0 = 3.4 × 10 20 N m) is used in the seismic inversion [ Mendoza and Fukuyama , 1996] and a 30‐km‐wide rupture ( M 0 = 4.85 × 10 20 N m) is used in the tsunami model [ Satake and Tanioka , 1995]; and (3) for the 1992 Flores Indonesia earthquake a 60‐km‐wide rupture ( M 0 = 7.5 − 8 × 10 20 N m) is used in the seismic inversion [ Beckers and Lay , 1995] and a 25‐km‐wide rupture ( M 0 = 6.4 × 10 20 N m) for the tsunami model [ Imamura et al , 1995]. Although rupture width is, in general, poorly constrained in seismic inversions, the rupture width required by the uniform slip model for tsunami generation is artificially small.…”

8. Earthquake sources of the Australian plate margin: revised models for the 2018 national tsunami and earthquake hazard assessments

“…Linking all of these structures together is based on geodetic block modelling (Koulali et al, 2016) and a lack of obvious structural boundaries that would prevent rupture across previously mapped back-arc segments, although fault mapping demonstrates that the back-arc is clearly structurally segmented and more complex than is practical to treat for assessing earthquake and tsunami hazard for Australia (Breen et al, 1989;Irsyam et al, 2010;. Source models for the largest instrumentally recorded earthquake on this structure, the 1992 M w 7.9 Flores earthquake and tsunami, show that this earthquake occurred further south than the incipient trench where the Flores Thrust is mapped, further demonstrating the complexity of the region (Beckers & Lay, 1995;Hidayat et al, 1995;Imamura et al, 1995;Griffin et al, 2015). Similarly, locations for the 2018 Lombok sequence of earthquakes (28 July M w 6.4, 5 August M w 6.9 and 19 August M w 6.9) are located south of the surface trace of the Flores Thrust.…”

Simulation on tsunami-like solitary wave run-up around a conical island using a modified mass source method

“…When facing a tsunami attack, the direct damages for an island are wave run-up and inundation. For instance, a tsunami in Indonesia in 1992 caused unexpectedly huge run-up heights on the lee shore of Babi Island, killing more than 700 people according to Imamura, Gica, Takahashi, and Shuto (1995) and Paris, Lavigne, Wassmer, and Sartohadi (2007). The 1993 Southwest Hokkaido earthquake tsunami caused great damage and losses around the southern part of Okushiri Island (Sato, 1996).…”